my BMW 3 Series F30/F31 (2012-2019) won't start just clicks what could it be

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, load tester, socket set, wrenches, and safety gloves.
• Ensure the vehicle is in a safe, well-ventilated area and the engine is turned off.

2. Battery Inspection

• Disconnect Battery: Use a wrench to disconnect the negative terminal first, then the positive terminal.
• Clean Terminals: Inspect for corrosion. Clean terminals with a wire brush and a solution of baking soda and water if corrosion is present.
• Reconnect Battery: Reconnect the positive terminal first, followed by the negative terminal.

3. Battery Testing

• Load Test: Connect the load tester to the battery and apply a load equal to half the battery's CCA (Cold Cranking Amps) rating for 15 seconds. A healthy battery should maintain above 9.6 volts.
• Replace Battery: If the battery fails the load test, replace it with a compatible battery (e.g., BMW Group 61-1121-111).

4. Starter Motor and Solenoid

• Locate Starter Motor: Refer to the vehicle's service manual for the location of the starter motor.
• Inspect Connections: Check the electrical connections to the starter motor and solenoid for tightness and signs of wear.
• Test Starter Function: Use a multimeter to check for voltage at the starter while an assistant turns the key to the start position. If there’s voltage but the starter does not engage, replace the starter motor.

5. Ignition and Neutral Safety Switch

• Check Ignition Switch: Ensure that the ignition switch is functioning correctly by testing for continuity in the ON and START positions.
• Neutral Safety Switch: If the vehicle is automatic, ensure the vehicle is fully in 'Park' or 'Neutral'. Test the neutral safety switch for proper function.